Add to Cart Freezes

Something in this form or plugin is causing WooCommerce to freeze when a user adds this product to their shopping cart. It just hangs.

But if you refresh the page, it shows that the item has been added to your cart, and the details from the form display correctly. It’s only hanging on the product page, when Add to Cart is clicked.

Any ideas?

The page I need help with: [log in to see the link]